1. Field of the Invention
The present invention relates to an LED lighting apparatus to turn on an LED.
2. Description of Related Art
A related art concerning an LED lighting apparatus for turning on an LED (Light Emitting Diode) is, for example, Japanese Unexamined Patent Application Publication No. 2011-210659 (Patent Literature 1). The LED lighting apparatus of this related art turns on and controls the LED with direct current.
The LED lighting apparatus of the related art includes a step-down chopper circuit. The step-down chopper circuit includes the LED that is turned on with direct current, an inductor and a switching element that are connected in series with the LED, and a regenerative diode that is connected in parallel with a series circuit of the LED and inductor. The regenerative diode is oriented in a direction to discharge accumulated energy of the inductor to the LED when the switching element is OFF. The LED lighting apparatus also includes a control circuit to turn on/off the switching element.
The control circuit includes a unit to turn off the switching element when an instantaneous value of an incremental current passing through the inductor during an ON time of the switching element reaches a predetermined value and a unit to turn on the switching element when a decremental current passing through the inductor reaches nearly zero during an OFF time of the switching element.